Method of molding shrink-head casings



Feb. 9 1926.

F. H. CHAPIN METHOD oF MOLDING SHRINK HEAD CASINGS Filed Sept. 16J 1925 2 Sheets-Sheet l ,Q "9

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Feb. 9 1926.

F. H. CHAPIN METHOD OF MOLDING SHBINK HEAD CASINGS 2 Sheets-Sheet 2 Filed sept le, 1925 @n w .Ril

Patented Feb.'9, 1926,.

' UNITED STATES ,FRED H. CHAPIN, OF CLEVELAND, OHIO,

l 1,572,705 PATENT oFFlca ASSIGNOB TO THE BOBiNE-FULLER COM- PANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

METHOD OF MOLDING .SHRINK-HEAD CASINGS.

Application filed. September 16, 1925. Serial No. 56,753.

or shrink head casing into which the molten metal rises during the latter part of the pouring operation and within which a pool of molten metal is maintained long enough to feed'the molten metal to the pipe orcavity naturally forming in the solidifying metal so that whatever pipe or cavity remains in the ingot will be confined within the casing or mold top, thus largely reducing the amount of metal cropped from the ingot before it is rolled into blooms or during the blooming process.

Usually shrink-head casings of this kind have been made of fire cla I have found, however, that the cost o such casings is very largely reduced by making them of blast furnace slag treated in a new Wa In my U. S. Patent No. 1,547 ,787 ofy July 28, 1925, I have shown and described a very eiiicient shrink head casing made of blast furnace slag and a binder suchas cement, treated with a substance which prevents the deleteriousaction of the gas-producing constituents of the mixture. I have found that while such casings are being molded they contract to a considerable extent and if the inner and outer walls of the mold in which such a casing is formed are lrigidly held until the material is fully set, hardened or solidified, internal, strains are produced which cause the casing to crack or break in various places.

To preventthe formation of these strains or stresses and consequent cracking or breaking of the casing, I have devised a `mold in which the material is molded or given shape between inner and outer walls provided with means for rigidly holding them in position until an initial shape 1s given to the material, but which can be released from the casing at different periods during the molding operation. In practice, the inner Walls are released as soon 'as the material has partially set., hardened Vtially solidified casing is allowed to remain eral shapeor form shown in my U. S. patent or solidified or as soon as a skin has beenl formed on the surface of the material suficiently strong to support the softer material within the skin. After this, the parwithin the outer mold walls until it has hardened to the desired extent when the outer mold walls are released and the casing removed and given further treatment i when required.

While the mold constructed in accordance with my invention is especially designed to make shrink head casings of the kind shown, described and claimed in my U. S. patent above mentioned, I have found that it is serviceable in molding casings made of properly treated liquid furnace slag and various other materials.

The novelfeatures of the mold construe# tion are claimed in my application for U. S.

patent, Serial No. 56,754 filed September 16, 1925. The claims herein are confined to a novel method of producing casings in accordance with my invention.

In the accompanying drawings I have illustrated the best wayzknown to me of carrying out my invention. n

Figure 1 is a perspective view of a mold constructed in accordance with my invention for making shrink head casings of the genof July 28, 1925. A

Figure 2 is a top plan view of the mold illustrating how the material is molded therein and indicating how the inner Walls of the mold are released from the casing after the material has partially set, hardened or solidified.

Figure 3 shows a vertical central section through the mold and the casing illustrating how the inner Walls of the mold are held rigidlyV during the initial part of the molding operation.

Figurei illustrates how the inner walls i of the mold are released from the partially formed casing..

Figure 5 shows how both the inner and outer lwalls of the mold are released from the casing.

Both the inner and outer walls of the mold comprise two similar members A and vtwo similar members B. The members A are of a generallrectangular shape being lof. the

same Awidth and height. The members B are "of the same size and shape and each of these members B has an inwardly projecting flange b at each end. The lower ends of the members A and B are seated in a bottom member C provided with a recess -o extending continuously around the inner side of the bottom member. The lower ends of the members A and B closely fit within the recess c in such manner that they can not be moved laterally in either direction. These recesses are wide enough to accommodate not only the lower ends of the members B including the anges b, but also the lower ends of the members A. This construction is clearly shown in the drawings. In order to hold the outer walls of the mold irml in place, I employ locking bars D whic have at opposite ends arms d which overlap the end portions of the members A. The distance between the two arms of each locking bar is such as to provide a space d to receive a wed e E. When the wall members A areplace in proper position and the locking bars D are applied, the wedges may be driven homein such manner' as to securely lock the members A in operative position. e f

The inner walls of the mold are. preferably made o fgeight separate pieces. There are four corner members F, all o f the samevsize and shape and four intermediate members G, all ofthe same size and shape. The members G are T-shaped,each having ortions g which overlap the inner ends o the corn'er members F and a'centralportion g which is adapted to enter' between the extreme-inner ends of two corner members. This is indicated by dotted lines in Figure 2. When the intermediate members G engage the corner pieces as shown by dotted lines in Figure 2, the inner wall of-.the mold as a whole is rigidly, held but when the intermediate members are withdrawn in the manner indicatedin Figure 2, the i er wall of thel mold is released from'the ma rial being molded.

In order to securely lock the er wall members in place, I employ loc n blocks or bracing b ocks H of the kin sown in Figure 3. Two such blocks may be used. They are somewhat longer than the distance .between two intermediate members when these members are in locked osition. -One -end of each block H may e curved or rounded1 as indicated at h and seated in a Y recess h'in one of the members G. The

opposite endv of the Vblock H may abut against the oplp'osite intermediate member G. AIt will be un 'ers'tood that only two lockin p' 'blocks H are necessary, one being employe between eachtwo intermediate members G. A locking ring L is adapted to be seated in rabbets or recesses Z formed in the upper ends of the members F and G. The lower ends of the members F and G project into a recess M in the middle portion of the bottom member C and when the ring L is applied and the blocks H are forced into active position the outer portions of the lower ends of the members F and G are pressed against the inner sides of a rib or flange N surrounding the recess M. The ring L and the fiange N limit the outward movement of the members F and G when the bracing blocks I-I are put under strain.

When the parts are in the condition shown in Figure 3, the material X to be molded may be poured in between the inner .and

' outer walls of themold and allowed to partially set, harden or solidify. In practice, it is found that a skin such as indicated at is formed along the material if the material is allowed to stand for a few minutes, sa

ten to fifteen minutes. This skin is su iciently stron to support the softer materia'l within t e skin. When the parts are.

in the condition shown in Figure 3, the material in a liquid, plastic or semi-Huid condition is oured into the space between the inner an outer mold walls in the manner indicated in Figure 3, and the material is a1- lowed to partially set, harden, or solidify in bracing blocks H are knocked out of o erative position, the inner walls of the mol collapse `in the manner indicated Ain Figure 4. In other words, they are withdrawn from contact with the casing bein formed so that the manner before described. After the 4 the casing is allowed to free y contract as it naturally. does during solidification. In this way, I prevent the presence of interior strains o r stresses in the casing which would occur if 'freedom of contraction was not provided for.

In ythe condition shown in F re 4, the mold is allowed to stand until t e material has set, hardened or solidified to the dei sired extent throughout the casin and then the locking bars are remove lowed to drop away from the casing in the -manner indicated in Figure 5. The casing is now completely molded.- It ma in some cases be used in this condition or 1t may be further treated in the manner-described in my patentr before mentioned or in other ways.

The mold walls or sections are of nonresilient or rigid material as shown in the drawings and inl the use of the Amold the sections are rigidly connected with each other b the fastening devices shown and the mo d walls can neither expand nor contract until the fastening devices are released. .p

It will thus be seen that my invention` involves not only a mold of novel construction but a novel method of 'molding the material from which the casing is made, such method not being confined to the parand all ticular construction of mold shown in the accom anying drawings and hereinbefore descri ed.

I claim as my invention.

1. The method herein described of mak ing shrink head` casings for ingot molds which consists in giving tubular shape to liquid or semi-plastic material while held against either expansion or contraction between rigid non-resilient inner and outer mold walls, allowing the 'material to partially set, harden or solidify, while so held, then releasing the material from the inner mold walls to allow the material to completely set, harden or solidify while surrounded by the rigid non-resilient outer walls of the mold, and to allow the article as a whole to contract inwardly and then separating the completed article from the outer mold walls. v

2. The method herein described of making shrink head casings for ingot molds which consists in giving tubular shape to liquid or semi-plastic material while held against expansion and contraction between rigid non-resilient inner and outer mold walls, allowing the material to set, harden,

or solidify sufficiently to form a supportin skin thereon, then releasing the 'mate ria from the inner mold walls to allow it to completel set, harden or solidify while surrounded y the rigid non-resilient outer walls of the mold, and to allow the article as a whole to contract inwardly and then separatin the completed article from the outer mo d walls.

3. The methodherein described ofY making shrink head casings for ingot molds which consists in giving the desired form 'to suitable material while confined between rigidly held inner and outer Walls against expansion or contraction, and then after the material has partially set, hardened or solidified, allowing the forming casing to freely contract while its inner walls are unconfined and its outer walls are closely surrounded by the rigid non-resilient outer mold walls until the article is completed, and then separatin the completed article from the outer mol walls.

Inl testimony whereof, I have hereunto subscribed my name. I

FRED H. CHAPIN. 

